Simultaneous existence of galactose-containing glycoprotein and several neuropeptides in DRG of the rat.

By use of light microscopic immunohistochemical and lectin histochemical methods, the interrelation of galactose-containing glycoprotein (GCGP), calcitonin gene-related peptide (CGRP)-like, leu-enkephalin (L-ENK)-like, and substance P (SP)-like peptides has been evaluated on consecutive sections of dorsal root ganglia from colchicine-treated rats. The results showed that GCGP, CGRP, L-ENK and SP exist simultaneously in individual neurons of the dorsal root ganglia in rats. Almost all small neurons in dorsal root ganglion contained both GCGP and CGRP. The stronger peanut lectin affinity with small neurons, the weaker CGRP immunoreactivity, and vice versa. Some neurons of medium size were of strong CGRP-like immunoreactivity; however, they lacked in affinity with peanut lectin. The large spinal ganglionic cells rarely showed CGRP immunoreactivity and affinity with peanut lectin. The results suggested that there was a negative interrelation between GCGP and CGRP in small primary sensory neurons. From the above it may be suggested that the GCGP plays an important role in recognizing and transmitting information in primary sensory neurons.